Toxicity literally means poisonous or noxious and, logos refers to the underlying science that explains the adverse effects of toxicity at the organismal level. Toxicology therefore means an multidisciplinary field which is at the interface of Biology, Chemistry and Medicine, with a special focus on Pharmacology. The subject discusses the presence of physical, biological and chemical agents in the Biological system and the way they affect its functions. Toxicology places special emphasis on the dosage of toxic substances, the route of exposure, species, age, sex, and the environment. Toxicology is a branch of science concerned with nature, effects, properties, detection and treatment of poison. It involves adverse effects of drugs and chemicals on living organisms including humans, diagnosis and treatment of poisoning.